On the Water Front

By ELIZABETH ROYTE

Published: February 18, 2007

ON a raw winter's day, the water riffling over the spillway of the Ashokan Reservoir looks icy and pure. Set at the eastern end of this vast artificial lake in Ulster County, the spillway curves and drops like a wedding cake, in four tiers, before sending its flow through a narrow granite passage flanked by evergreens. The setting is grand, as befits an enormous public work, a manipulation of nature for the benefit of humanity -- or at least for the 8.2 million residents of New York City, 100 miles to the south.

If the Ashokan is not the one true source of the city's drinking water, akin to Perrier's Verg? or the original Poland Spring, it is still evocative shorthand for the sprawling upstate waterworks that have long quenched New York's thirst. The city has the largest drinking-water system in the country, an engineering feat on a par with the Panama Canal, delivering 1.2 billion gallons of water a day through 300 miles of tunnels and aqueducts and 6,000 miles of distribution mains.

Moreover, as city officials, water connoisseurs and native boosters have long declared, New York tap water is among the world's purest and tastiest. It is praised in foreign-language guidebooks, and some city bakers credit its mineral content and taste for their culinary success.

''It's delicious,'' said Emily Lloyd, commissioner of the city's Department of Environmental Protection.

The upstate water is of such good quality, in fact, that the city is not even required to filter it, a distinction shared with only four other major American cities: Boston, San Francisco, Seattle and Portland, Ore. New Yorkers drink their water from Esopus Creek, from Schoharie Creek, from the Neversink River, straight from the city's many reservoirs, with only a rough screening and, for most of the year, just a shot of chlorine and chasers of fluoride, orthophosphate and sodium hydroxide.

But that state of affairs may not last. In late spring or early summer, the United States Environmental Protection Agency will decide whether New York water is still pure enough to drink without filtering. Development in the city's upstate watershed areas, as well as the increasingly stormy weather that comes with climate change, is threatening the water's mythic purity. If the federal agency does conclude that city water is too sullied to be consumed directly, New York will have to spend huge sums on filtering, close the book on 165 years of filter-free taps -- and absorb a major blow to its hometown pride.

When the Dutch arrived in Manhattan four centuries ago, they drank from the same creeks and springs as the Algonquin Indians who preceded them. As the colony grew, these local sources became polluted. Residents collected rainwater for drinking, but the preferred beverage during those years was beer.

In 1666, the new English governor of New York dug the city's first public well. Wells would provide water for the next two centuries, but the water, distributed through wooden mains, was brackish and hard. Eventually the wells became contaminated by industrial byproducts and by animal and human waste; in the 18th century, New York was desperate for a new approach.

For decades, city planners squabbled over alternative sources of water, looking as far away as Lake George in the Adirondacks and the Housatonic River in Connecticut. Finally, in the 1820s, they decided to impound the waters of the Croton River in northern Westchester County and send 90 million gallons a day through an aqueduct to the city. But by the time the system was completed in 1842, Manhattan already needed more water.

From that point on, the water system grew just as New York did. The city expanded its watershed into the Catskills, built immense aqueducts and relocated thousands of people, and even graves, to create huge reservoirs like the Ashokan.

Today, New York water originates in watersheds that sprawl over nearly 2,000 square miles, filling 19 reservoirs and three controlled lakes. The aesthetic and mechanical beauty of the system -- 95 percent of which is gravity-fed -- causes some officials to wax sentimental. ''It's miraculous that the system replenishes itself,'' Ms. Lloyd said. ''And if we take care of it, it will provide drinking water for New York forever.''

Purity, Beset

Whatever the fabled deliciousness of New York's water, its residents, like other Americans, are drinking more and more of the bottled variety. ''I think it's convenience more than anything,'' Ms. Lloyd said about the trend. ''New Yorkers spend very little time at home -- they're the great grab-and-go eaters and drinkers.''

Or perhaps they are just suckers for ads that equate glaciers with purity and tropical islands with smooth taste. In 2003, Brita ran an ad campaign in the subways claiming that its filters turn ''even New York tap water into drinking water.'' Incensed, Christopher Ward, then the city's environmental protection commissioner, accused the company of fear-mongering, at which point the company withdrew the ads.